Does dialectal spelling of a name qualify as loc_name? E.g. a name that would spell with letter “V” in the local dialect instead of “L”?
I think I’d use alt_name in that case, assuming the pronunciation is the same or similar. Most uses of
loc_name relate to ones which are distinctly different in speech, e.g., Barlick instead of Barnoldswick, Stabbo instead of Stapleford. Incidentally, these English examples may not have a conventional orthography at all, as they are more-or-less only used in informal speech (and also when these have been mapped, there has not been an attempt to capture how the sound in local dialect, e.g., Top House in Bramcote sounds more like Top 'Ahse).
I would use loc_name if the dialect name is locally in common use. Many villages here in Germany for instance do have dialect names which are in common use by most of the villagers so these clearly qualifiy as loc_name imho.
If the local dialect has an ISO 639 code, use
name:lang=Name With V. Otherwise,
loc_name=Name With V is okay.